This invention relates to a surgical fastener cartridge adapted for use with an actuator apparatus for simultaneously applying a plurality of surgical fasteners to body tissue.
Surgical stapling apparatus in which a plurality of surgical fasteners are applied substantially simultaneously to produce an array of surgical fasteners are known. Typically, these apparatus include a fastener holder disposed on one side of the tissue to be fastened, an anvil assembly parallel to the fastener holder on the other side of the tissue to be fastened, means for linearly translating the fastener holder and the anvil assembly toward one another so that the tissue is clamped between them, and means for driving the fasteners from the fastener holder so that the ends of the fasteners pass through the tissue and form finished fasteners as they make contact with the anvil assembly, thereby producing an array of finished fasteners in the tissue. The term "fasteners" is used herein as a generic term for metal surgical staples, the staple-shaped portion of two-part resinous surgical fasteners, and their equivalents. Similarly, the term "anvil assembly" is used herein as a generic term to include the anvil used to clinch metal surgical staples, the retainer holder and retainer member of two-part resinous surgical fasteners, and the equivalent of these elements.
In common use are apparatus in which the fastener holder and anvil assembly comprise a disposable cartridge removably mounted in or on a permanent actuator for supporting and actuating the cartridge. The cartridge is disposable after a single use. The permanent actuator is reusable in the same surgical procedure after reloading with a fresh cartridge, and is reusable in another surgical procedure after cleaning, sterilizing, and reloading. Also available are disposable surgical apparatus, in which the cartridge and actuator are preassembled, ready for use, and are then disposed of after a single use.
Although instruments of the type described above are available for performing several different types of surgical stapling procedures requiring instruments and staple arrays of various configurations, an illustrative type of instrument is the so-called thoracic-abdominal surgical stapler, which is typically used for forming a row of staples laterally through hollow body organs such as the thorax, trachea, stomach, uterus or intestines.
U.S. Pat. No. 4,665,916, the contents of which are incorporated by reference herein, describes a surgical stapler apparatus of the foregoing type featuring a fastener cartridge of improved design and operation. The cartridge includes an alignment pin to achieve and maintain proper relative positioning of the fastener holder and anvil components thereof. When it is about to be actuated, the surgical stapler of U.S. Pat. No. 4,665,916 is positioned in such a way that tissue to be stapled is clamped in place between the fastener-ejecting surface of the holder and the surface of the anvil. Clamping pressure exerted against both sides of the tissue is sufficient to provide effective hemostasis along two linear sites which, upon actuation ("firing") of the instrument, receive parallel rows of staples on either side of an incision formed by tissue cutting means, also incorporated in the holder, whose deployment is mechanically synchronized to immediately follow the insertion of the fasteners. The magnitude of this clamping pressure is not so great, however, as to cause irreversible tissue trauma (necrosis).
In a Cesarean birth, a fetus is delivered by surgery which requires an incision through the uterus (hysterotomy). Because of the blood-rich nature of uterine tissue, it is especially important to achieve rapid and effective hemostasis for the length of the incision. However, due to the stretched, or taut, condition of the uterine wall at the time a Cesarean sectioning is performed, there is a tendency when employing conventional surgical instruments similar to that of U.S. Pat. No. 4,665,916 for the tissue to pull away from the fasteners after the incision is formed. Any actual pulling away of tissue from the fasteners poses the risk of substantial damage to the tissue in this region.
It is therefore an object of the present invention to provide a surgical stapler which minimizes or eliminates the possibility of tissue pulling away from the fasteners after the latter are positioned in place and the incision is made and until clamping pressure is released.
It is a particular object of the invention to provide a fastener cartridge which transfers the pulling tendency of tissue which is under tension away from the fastener line to a site which is remote therefrom.